What Causes the Abnormal Noise During Cold Start of Mistra?
2 Answers
The abnormal noise during cold start of Mistra is generally caused by the loss of lubrication in the internal gears of the starter, leading to stiffness and jamming, which affects the timely return of the gears. Detailed explanation of the principle: When starting the engine, the starter rotates to drive the flywheel, thereby starting the engine. At this point, the engine speed is driven by the starter, so the engine speed is lower than that of the starter. When the engine speed exceeds the starter speed after starting, the ignition switch is manually turned off, and the starter shuts down. Due to internal dirt and ineffective lubrication in the starter: The flywheel forces the starter to operate at its own speed, and the speed difference between the two causes the starter to produce the "screeching" noise that is heard.
The other day my neighbor came over in his Mistra, complaining about an annoying squealing noise from the engine compartment during cold starts. I popped the hood and listened carefully – it’s most likely an issue with the belt system. In cold conditions, belts harden and slip, especially noticeable in winter. Worn-out belts or a loose tensioner pulley often cause this squealing. Another common culprit is a starter that doesn’t fully disengage, creating a metal scraping sound as it rubs against the flywheel. My advice: first check the belt for cracks. Sprinkle a few drops of water on it – if the noise disappears, that confirms it. Hydraulic lifters might also tap briefly before oil circulates, but that’s less concerning. If metallic knocking persists beyond 10 seconds, head straight to the shop to check major components like crankshaft bearings.
